Water-tube boiler.



GEORGE T. LADD, OF PITTSBURGH, PENNSYLVANIA.

WATER-TUBE BGILER.

Specication of Letters Patent.

Patenten nec. 5,1916.

Application filed August 11, 1915. Serial No. 45,031.

To all whom it may concern: A

Be it known that I, GEORGE T. LA-DD, residing at Pittsburgh, in the county of Alleghenyand State ofPennsylvania, a citizen of the United States, have invented or discovered'certain new and useful Improve- .ments in W aterfTube Boilers, of which 'Improvements the following is a specification. The mvention described herein relates to certain improvements 1n the manner of baiiiing the Milne type of water tube boiler,

consisting of upper and lower drums corr nected by a Central set of tubes and two sets 'j' or posts of tubes arranged on opposite sides of the central set or nest. It has heretofore been the .practice to arrange a baille against the innermost row of tubes of the set next adjacent to the `fire-chamber, so that the products of combustion as they pass from the fire boxflow up between the tubes of this Y ,I set to a' plane near the upper drum. The products of combustion then pass over this rst baille andow down through the space A between the first-and central set of ltubes and along this set of tubes, a baiiie extendl ing down from the upper drum alongside the rowr of tubes on the stack side of such set. This second baiie extends down nearly to the lower end, and the products of combustion pass around its lower end and How up along the third or stack set of tubes to -1 the stac Experience has shown that asvthe gases flow up along the first set of tubes, those portions in Contact with the tubes are cooled and retarded, and the gases intermediate the cooled layers or strata flow more rapidly ,and that as there is no provision made in the passes for mixing the gases, the stratification thus established is maintained to a greater or less degree during the movement ofthe gases to the stack. The gases flowing from among the tubes of the first set and over the upper end -of the first baffle, move down the space between the first and l.econd sets of tubes and along the tubes of the second set in planes approximatelyparallel with the llines of flow or stratification established during the flow along` the first set of tubes. In passing under the second baffle and up along the tubes of the third set, the Straticationoriginally established is not materially disturbed and the gaseIescape-at a high temperature into the star.

The invention describ/ed herein hasiei its object an arrangement of baiing, which will cause' the gases to 'move through the nest .of tubes adjacent to one end and back through the same set intermediate of the ends and a third time adjacent to the opposite end,` the gases after each movement transverse of the tubes enter an open Space or chamber where the cooled and hot gases 'can intermingle.-

The invention is hereinafter more fully described and claimed.

In the accompanying drawing forming. a part of this specification is shown a sectional elevation of aMilne type of boiler having my improved baffling applied thereto.

The boiler consists of upper and lower drums 1 and 2, and three sets of tubes 4i, 5

and 6 connecting said drums. A horizont:-

bafiie 7 is arranged approximately in line with the top of the i'ire box and extends nearly to the outer tubes of the firstset 4, so that the products of combustion as thev -flow from the fire box will be caused for the most part: to pass between the tubes of this first set into the space or mixing chamber S l between the first and central set :5. The

gases on entering this chamber impinge on" drum. A considerable volume of the gases Will of course iow up along the tubes of the first set, but after they have passed above the horizontal baffie, their vertical flow will be disturbed by the gases from the mixing chamber moving outwardly or to the left. This outward movement from the mixing chamber 8 being due in part to the draft, but principally to the deiiection caused by the inclined baiile 16 forming the' upper end of a mixing chamber. By reason of the intersection of the two streams or lines of flow, one parallel and along the tubes and the other at an angle to the tubes, a thorough mixing of thc gases will be effected in the space or chamber 10 to the left of the first set of tubes. From this mixing chamber 10 the gases pass in a nearly horizontal direction through the first and central sets of tubes into -a mixing chamber 11 formed by spacing the central and thirds'ets of tubes apart. The gases are tubes; a bale arranged between-thesecond n this baiie ,"will be deected among the 'central set of tubes Where they will mingle with gases {iowing down along such tubes. The greatest deflection of the gases inthechaln-` ber llfwvill lie-effected by the baie 13 forming the lower'end of said chamber.. As the' gasespass below the bale l'they are caused to `rnove'across 4the central set-a third'tixne intoV another mixing spaceA or chamber 14.

From this space the gases 'flow -upward I along the tubes of the third or stack set of tubes, and the space between such tubes and the side Wall: of the boiler' setting. If'such space is uninterruptedand there might-bev a'tendencyv for the ,gases to'moye .fromA` be tween the tubes into suchspaces it is pre# ferred to arrange ahorizontal baie'-15 a' l suitable point to compellateral dlverslon among the tubes of the stackl set. Thel ern--V ciencyl of this mode of baiing isshcfwn by the; fact that the temperatureof thel gases. in the stack is materially lowerthan when the old system was employed.

I: claim herein as my invention: l". .A boiler' having :in combination an .up-

pefrand a lower drum, three setsxof tubes connecting said druni; a bathe-arranged at auf angle to the first set of tubes and adapted tdfcause products of combustion r'oxny the Afire boxto ow across the lower 'ends of the first set-oi tubes; a-baie arranged between the first and second sets of tubes adjacent to `their upper endslnd adapted to cause proddots of combustion to flow transverse ofthe first set of tubes; a baie for preventing I' roducts of combustion from-flowing from -v etween the space between the" irst and s'ec;

'ond -setsfof tubes across the second set of and third' sets 'of tlibes. adjacent to their lloWer ends and adapted to cause products of combustion t flow transverse of -the second 'or intermediate set of tubes, and a verti Acally arranged baffle adapted to prevent the 'How of 'productsrof combustion transverse ofthe upper portions ofthe third set of tubes.

' 2. A boiler having in combination an upper and a lower drum, three sets of tubes connecting said drums, a-baiile arranged on the side 'of the intermediate set adjacent to the {ire-boxandV a second baffle 'arranged along the inner row Vof tubes of the .set ad` jacent to the stack, said b aie extending down from-'the upper toward the lower 3a boiler having in combination an upconnecting said drum, a baie arranged on the side of the intermediate set adjacent to the lire box and extending vertically 'front "the lower drum toward the upper drum, a

'baiile for deflecting the products of combustion lacross the first setof tubes near the upper.- portions thereof, a baile arranged along the' inner row'of tubes of the Set adjacent to thel stack and extending down from the upper drum toward the. lower drum,'anda baie `for directing the productsof combustion -transverse of the inter- -medlate vset of tubes near the lower ends of the latter. 4

In testimony whereof, I have hereunto set my hand. y y GEORGE 4T.'LADD.

'Witnessesz .ALICE A. TRILL, Trios. B. Joron. 

